The present invention relates to a new and improved construction of a controlled-deflection roll having a stationary roll support or carrier and a tubular roll shell which is rotatable about such stationary roll support, the tubular roll shell bearing on the roll support by means of at least one bearing or support element. Further, the roll shell is provided at its ends with guide members which are rotatably mounted in the roll shell and which are guided on the roll support in the direction of the pressing or disengaging movement of the roll shell.
Controlled-deflection rolls of this type -- sometimes referred to in the art as rolls with bending compensation -- are known, for instance from U.S. Pat. Nos. 3,802,044 and 3,885,283, corresponding to Swiss Pat. Nos. 556,946 and 571,904 respectively. With rolls of this type, it is possible to compensate for deflection in rolling mills where the rolls cooperate with a backing roll or counter-roll, and it is even possible to carry out a desired adjustment of the course of the roll deflection i.e. the pressing or contact force. Controlled-deflection rolls are therefore increasingly used for instance in papermaking machines and in textile processing.
In certain fields of application, for instance in papermaking machines, the controlled-deflection roll has to be fitted with a scraper device having a scraper blade which scrapes clean the surface of the roll shell. This operation assists, for instance, a rolled web from being disengaged from the roll shell or to clean the surface thereof. The scraper blade is accurately adapted to the surface of the roll shell, and the roll surface must possess a very high quality, whether it be formed of metal or for instance rubber.
Oftentimes it is also required that the pressing or contact roll, in other words, whichever roll of the pair applies the pressing or contact force, be disengageable from the backing roll so that the rolling mill can be opened. In the case of the heretofore known solid rolls having an external contact or pressing mechanism, it is usual practice to secure the scraper device to the roll levers and to move such together with the roll.
However, when there is employed as the pressing or contact roll a controlled-deflection roll of the type referred to, then the positioning of the scraper device leads to difficulties, since it cannot be mounted in the manner possible on solid rolls and the roll support does not move together with the roll shell.